Apparatus for preventing motor overload of vacuum cleaner

ABSTRACT

A motor overload preventing apparatus for a vacuum cleaner includes a damper body and an resilient member. The damper body has an opening/closing portion formed on one end, to selectively block a tapered aperture of a body frame of the vacuum cleaner, and the opening/closing portion is tapered to correspond in shape with the aperture. The resilient member resiliently biases the opening/closing portion toward a direction of closing the aperture. The damper body is movably disposed to rotate so as to selectively open and close the aperture, and to this end, it is preferred that the damper body is connected by a hinge to the body frame. Satisfactory sealing can be ensured even when there is surface contact between the opening/closing portion and the aperture without requiring additional material, such as a rubber. Additionally, the number of components can be reduced, and with the omission of flexible material, such as rubber, the manufacturing costs can be reduced.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a vacuum cleaner, and moreparticularly, to an apparatus for preventing overload of a driving motorwhen it generates a suction force for a vacuum cleaner.

2. Description of the Related Art

Generally, a vacuum cleaner draws in air and entrained dust by using asuction force that is generated by a driving motor. FIG. 1 schematicallyshows such a conventional vacuum cleaner.

Referring to FIG. 1, a conventional vacuum cleaner includes a body 10 inwhich a driving motor 1 is mounted, a suction pipe 3 which is in fluidcommunication with the body 10 at one of its ends and a suction nozzle 5which is formed at the other end of the suction pipe 3 from the endconnected to body 10. The body 10 includes a motor housing portion 11,in which the driving motor 1 is disposed, and a dust collecting housingportion 13, that includes a filtering portion 7 for filtering andcollecting dust drawn in through the suction pipe 3. The motor housingportion 11 and the dust collecting housing portion 13 are divided fromeach other by a partition 15.

The suction pipe 3 contains and transfers the dust from the suctionnozzle 5 and directs it toward the dust collecting housing portion 13.It is preferably made of a flexible material.

The vacuum cleaner constructed as above, draws in dust through thesuction nozzle 5 by using the suction force that is generated by thedriving motor 1. The air and entrained dust are passed through thesuction pipe 3 and the dust is collected in the filtering chamber 7inside the dust collecting housing portion 13. The air, after it isfiltered at the filtering chamber 7, is discharged to the outside of thebody 10 through a discharging section 11 a, which is formed at a rearside of the motor housing portion 11.

However, when the filtering chamber 7 is filled with dust, or if thesuction pipe 3 becomes clogged, fluid communication through the systemis hampered, and therefore, the driving motor 1 suffers an overloadcondition as a result of lack of available air in the suction process.In order to prevent undesirable damage to the driving motor 1 due tosuch an overload condition, there is usually provided a motor overloadpreventing apparatus 20, which permits external air flow into the dustcollecting housing portion 13.

FIGS. 2A and 2B illustrate in cross-sectional views one example of aconventional motor overload preventing apparatus 20. Referring now toFIGS. 2A and 2B, the conventional motor overload preventing apparatus 20includes a casing 21, a resilient member such as spring 23, anopening/closing member 25 and a flange portion 27.

The casing 21 defines a space for receiving the spring 23 and theopening/closing member 25. One end of the casing 21 is open, while theother end is formed with a plurality of holes 21 a, as shown in FIG. 2B.The casing 21 is also fixed to the partition 15 by the flange portion 27within an opening 15 a of the partition 15, which divides the motorhousing portion 11 from the dust collecting housing portion 13.

The flange portion 27 is formed in an annular or ring shape with acentral hole formed therein so as to hold the open end of the casing 21securely against the partition 15.

The opening/closing member 25 is formed of a material, such as rubber,to ensure tight sealing capability within the opening 15 a. The member25 selectively opens or closes the ring-type flange portion 27 dependingon the relative pressure, as will be explained below. Theopening/closing member 25 has a plurality of holes 25 a formed tocorrespond to a ring having a diameter outside of the diameter of a hole27 a at a central location formed in the flange portion 27. When theopening/closing member 25 engages the flange portion 27, it closes thehole 27 a of the flange portion 27, and simultaneously the flangeportion 27 selectively blocks the holes 25 a of the opening/closingmember 25.

The spring 23 is interposed between the other end of the casing 21 andthe opening/closing member 25, and resiliently biases theopening/closing member 25 toward the direction of the flange portion 27,thereby maintaining the closed condition of the hole 27 a.

According to the conventional motor overload preventing apparatus 20,constructed as above, if the filtering portion 7 becomes clogged withdust or the suction pipe 3 becomes obstructed during the operation ofthe vacuum cleaner, thereby causing a negative pressure to be generatedinside the dust collecting housing portion 13, the opening/closingmember 25 as a result of the negative pressure, overcomes the resilientrecovery force of the spring 23 and is transposed toward the dustcollecting housing portion 13, and thereby retracts the opening/closingmember from the hole 27 a.

Accordingly, the opening/closing member 25 does not block the ring-typeflange portion 27, and an external air flow is introduced inside thedust collecting housing portion 13 through the hole 27 a of thering-type flange portion 27, and the holes 25 a of the opening/closingmember 25 and holes 21 a of the casing 21, thus preventing overloadconditions of the driving motor 1.

However, the motor overload preventing apparatus 20 requires an overlycomplex structure. Further, because the opening/closing member 25 isusually made of expensive material, such as rubber, in order to ensuresufficient sealing of the opening/closing member 25, manufacturing costincreases.

SUMMARY OF THE INVENTION

In an effort to overcome the above-mentioned problems, it is an aspectof the present invention to provide a motor overload preventingapparatus for use in a vacuum cleaner which has a simple structure andwhich can reduce inconvenience that results from a requirement foradditional material, such as rubber, while ensuring a sealing of anopening/closing member.

In order to accomplish the above aspect and/or other features of thepresent invention, an apparatus for preventing motor overload conditionsof a vacuum cleaner includes a damper body having an opening/closingportion formed adjacent a first end to selectively block a taperedaperture extending through a body frame of the vacuum cleaner, theopening/closing portion being tapered to correspond in shape with thetapered shape of the aperture, and a resilient member to resilientlybias the opening/closing portion toward a direction of closing theaperture.

According to one preferred embodiment of the present invention, thedamper body is mounted and movably disposed to rotate so as toselectively open and close the aperture, and to this end, the damperbody is preferably connected to the body frame and is transverselytransposable to selectively open and close the aperture.

The resilient member preferably comprises a plate spring having two endswhich engages and overlaps the damper body adjacent a first end, and thesecond end engages and overlaps the body frame adjacent the second end.

According to the preferred embodiment of the present invention, in orderto adjust the recovery force biasing the resilient member toward thebody frame, a hinge portion of the body frame on which the other end ofthe resilient member is mounted protrudes from the body frame and therecovery force may be made adjustable by adjusting the position of theplate spring.

The hinge portion of the body frame is adjustable in the height to whichit protrudes from the surface of the body frame of the vacuum cleaner.

The apparatus for preventing motor overload constructed as above can bemounted in the partition which divides a motor housing, where a drivingmotor of the vacuum cleaner is disposed, from a dust collecting housing,where a dust filtering portion is placed. Alternatively, the motoroverload preventing apparatus can also be mounted on the frame of thedust collecting housing.

Meanwhile, according to a second preferred embodiment of the presentinvention, there is provided a cap portion disposed adjacent the secondend of the damper body. The resilient member preferably comprises a coilspring interposed between the opening/closing portion of the damper bodyand the cap portion.

The coil spring is shaped and configured having a diameter that islarger than the smallest diameter of the tapered opening/closing portionof the damper body, and is larger than the smallest diameter of theaperture.

Further, the damper body comprises a plurality of holes to permit air toflow therethrough, and the plurality of holes extend in a lengthwisedirection of the damper body so as to define posts.

The above-described apparatus for preventing motor overload constructedcan be mounted on the partition which divides a motor housing, where adriving motor of the vacuum cleaner is placed, from a dust collectinghousing, where a dust filtering portion is placed. Alternatively, themotor overload preventing apparatus can also be mounted on the frame ofthe dust collecting housing.

Instead of forming the opening/closing portion with additional material,such as rubber, satisfactory sealing can be ensured by tapering theopening/closing portion and the aperture even when surface contactoccurs between the opening/closing portion and the aperture.Additionally, the number of components can be reduced, and with theomission of expensive flexible material, such as rubber, themanufacturing cost can be reduced.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The above aspects and other features of the present invention willbecome more apparent by describing in detail preferred embodimentsthereof with reference to the attached drawings, in which:

FIG. 1 is a partial cross-sectional view of a conventional vacuumcleaner;

FIGS. 2A and 2B are cross-sectional views illustrating the operation ofa motor overload preventing apparatus of the conventional vacuumcleaner;

FIGS. 3A to 3C are, respectively, an exploded perspective view, a frontview and a side view, illustrating a motor overload preventing apparatusaccording to a first preferred embodiment of the present invention;

FIGS. 4A and 4B are side views illustrating in partial cross-section theoperation of the motor overload preventing apparatus as shown in FIGS.3A to 3C;

FIGS. 5A and 5B are, respectively, an exploded perspective view and aside view, showing a motor overload preventing apparatus according to asecond preferred embodiment of the present invention; and

FIGS. 6A and 6B are side views illustrating the operation of the motoroverload preventing apparatus shown in FIGS. 5A and 5B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described in detail withreference to the accompanying drawings. Throughout the description, theelements similar to, or identical with, those described in thebackground art as illustrated in FIGS. 1 and 2A-B will be identified bythe same reference numerals and further detailed description of thestructure and function thereof will rely on the description made above.

FIGS. 3A-C and 4A-B are views of a motor overload preventing apparatusfor use in a vacuum cleaner according to a first preferred embodiment ofthe present invention.

Referring now to FIGS. 3 and 4, the first preferred embodiment of themotor overload preventing apparatus 100 includes a damper body 101 and aresilient member 107.

A tapered opening/closing portion 101 a is formed in an end of thedamper body 101, while the other end of the damper body 101 is connectedto the partition 15 of the vacuum cleaner by a hinge, as shown. Morespecifically, the damper body 101 is connected to the partition 15 bythe cooperation of rotary axes 101 b, which laterally protrude from bothsides of the other end of the damper body 101, and hinge mounts 115,each having an axis hole on which the two opposite ends of rotary axis101 b is turnably seated, are disposed on the partition 15.

The tapered opening/closing portion 101 a is shaped and configured toenable it to block a corresponding tapered aperture 113 of the partition15 that divides the motor housing 11 from the dust collecting housing13. The tapered aperture 113 is tapered so as to correspond to the shapeof the tapered opening/closing portion 101 a. The opening/closingportion 101 a and the aperture 113 are each tapered so as to ensuresufficient sealing capacity therebetween as a result of surface contactof the tapered surfaces. Accordingly, there is no need to provide to theopening/closing portion 101 a any additional material such as rubber,and therefore, manufacturing costs can be reduced.

The resilient member 107 resiliently biases the damper body 101 towardthe direction where the opening/closing portion 101 a of the damper body101 closes the aperture 113 of the partition 15. According to onepreferred embodiment of the present invention, the resilient member 107further comprises a plate spring, and more preferably comprisesstainless spring steel.

In the present embodiment, in order to allow the resilient member 107 toattach to the damper body 101 more securely, one end of the resilientmember 107 is overlaps the damper body 101, while the other end isoverlaps with the partition 15. The partition 15, where the other end ofthe resilient member 107 is mounted, includes a fixing portion 111disposed thereon which protrudes so as to cause the resilient member 107to have a predetermined resilient recovery force biasing the springtoward the partition 15. Due to the fixing portion 111 of the partition15, the resilient member 107 resiliently biases one end of the damperbody 101 toward the aperture 113 of the partition 15.

Also, in order to facilitate the overlap of the resilient member 107,resilient member receiving portions 101 c, 111 a (FIG. 3A) are formed toengage each other at the other end and the fixing portion 111 of thedamper body 101.

The fixing portion 111 of the partition 15 is preferably adjustable inthe height to which it can protrude above the surface of partition 15.Accordingly, the resilient recovery force can be adjusted appropriatelyby adjusting the protruding height of the fixing portion 111 withoutbeing influenced by the elastic modulus of the resilient member 107.

The operation of the motor overload preventing apparatus 100 will bedescribed below. When there is dust undesirably clogging the filteringportion 7 or when the suction pipe 3 is obstructed by dust or otherobstruction, negative pressure is generated inside the dust collectinghousing 13. Because of the negative pressure, the opening/closingportion 101 a of the damper body 101 is able to overcome the resilientrecovery force of the resilient member 107, and consequently it rotatesabout the rotary axes 101 b in a counter-clockwise direction away fromaperture 113 and toward the dust collecting housing 13, as shown in FIG.4A.

As the opening/closing portion 101 a is rotated, the aperture 113 of thepartition 15 is opened, and therefore, flow of external air isintroduced into the dust collecting housing 13. By the external air flowbeing introduced, overload conditions of the driving motor 1 can beprevented.

Meanwhile, as the dust of the filtering portion 7 is borne away by theair flow, or the suction pipe 3 again achieves fluid communication, thenegative pressure is lessened to below a certain degree so that thedamper body 101 cannot any longer overcome the resilient recovery forceof the resilient member 107. Accordingly, the damper body 101 is rotatedby the resilient member 107 in a clockwise direction toward the aperture113 so as to block the aperture 113 in the partition 15, as shown inFIG. 4B.

Meanwhile, FIGS. 5A and 5B are exploded perspective and side views,respectively, of a motor overload preventing apparatus 200 for use in avacuum cleaner according to a second preferred embodiment of the presentinvention. Referring to FIGS. 5A and 5B, the motor overload preventingapparatus 200 includes a damper body 201 and a resilient member 203.

A tapered opening/closing portion 201 a is formed adjacent one end ofthe damper body 201, and a cap portion 205, which will be describedbelow, is formed adjacent the other end of the damper body 201. The capportion 205 may be separately made and attached to the damper body 201,as shown. Alternatively, the cap portion 205 may be integrally formed aspart of the damper body 201. The tapered opening/closing portion 201 ablocks the aperture 215 of the partition 15 which divides the motorhousing 11 from the dust collecting housing 13, and the aperture 215 isalso tapered to correspond in shape to the taper of opening/closingportion 201 a.

Because of the tapered shape of the opening/closing portion 201 a,sufficient sealing capacity can be ensured even when surface contactbetween the opening/closing portion 201 a and the aperture 215 ispresent. Accordingly, there is no need to employ additional material,such as rubber, to ensure sealing between the aperture 215 and theopening/closing portion 201 a, and thus manufacturing costs can bereduced.

Further, there is a plurality of slots 201 b formed in the damper body201 so as to permit air to pass therethrough. According to the presentembodiment, the slots 201 b are extended in the lengthwise direction,and the slots 201 b define a plurality of posts 207, which are arrangedannularly around a central longitudinal passage 209.

The cap portion 205, at the other end of the damper body 201, also has aplurality of holes 205 a to permit air to flow therethrough. The capportion 205 is biased against protrusions at the end of the posts by theresilient member 203 so as to retain it in place and inhibit it fromseparating from the mounting mechanism.

The resilient member 203 resiliently supports and biases the damper body201 toward the direction where the opening/closing portion 201 a of thedamper body 201 closes the aperture 215 of the partition 15. In thepresent embodiment, the resilient member 203 is a coil spring. The coilspring 203 is interposed between the opening/closing portion 201 a ofthe damper body 201 and the cap portion 205.

One end of the coil spring 203 engages the partition 15, while the otherend engages the cap portion 205. It is preferred that the coil spring203 has a diameter larger than the smallest diameter of the taperedopening/closing portion 201 a of the damper body 201, and also largerthan the smallest diameter of the tapered aperture 215 of the partition15. By this construction, the coil spring 203 is supported by the wallof the partition 15 even when the damper body 201 moves laterally, andthus can exert a predetermined resilient recovery force to bias the capportion 205 away from the partition 15.

The operation of the overload preventing apparatus 200 constructed inaccordance with the above described embodiment will be described belowin more detail.

When there is dust clogging the filtering portion 7 or when the suctionpipe 3 is obstructed by an object or by collected dust, negativepressure is generated inside the dust collecting housing 13. As a resultof the negative pressure, the opening/closing portion 201 a of thedamper body 201 overcomes the recovery force of the coil spring 203 andcauses the damper body 201 to move toward the dust collecting housing13, as shown in FIG. 6A. One end of the coil spring 203 engages thepartition 15, and the other end engages the cap portion 205 a. Togetherwith the damper body 201, the cap portion 205 a is also transposedtoward the partition 215 by the pressure of the external atmosphereapplied to the opening/closing portion 201 a, and by the movement of thecap portion 205 a, the coil spring 203 is compressed.

As the opening/closing portion 201 a is transposed to open the aperture215 in the partition 15, external air flow is introduced into the dustcollecting housing 13, and therefore, prevents overload of the motor 1.

Meanwhile, with the dust of the filtering portion 7 being cleaned, orthe obstruction in suction pipe 3 being removed so as to resume fluidcommunication, the negative pressure is lessened to below the thresholdamount so that the damper body 101 is not impelled to overcome theresilient recovery force of the coil spring 203. Accordingly, as shownin FIG. 6B, the damper body 201 is transposed toward the motor housing11 by the resilient recovery force of the coil spring 203, andtherefore, the opening/closing portion 201 a re-blocks the aperture 215of the partition 15.

Although the preferred embodiments are described above for purposes ofillustration and description, the invention is not to be consideredlimited by the above description, but is to be considered as includingany modifications, changes and alterations and the invention is to belimited only by the following claims.

1. An apparatus for preventing motor overload during operation of avacuum cleaner, comprising: a damper body having an opening/closingportion formed adjacent to a first end to selectively block a taperedaperture extending through a body frame of the vacuum cleaner, theopening/closing portion being tapered to correspond in shape with thetapered shape of the aperture; and a resilient member to resilientlybias the opening/closing portion toward the direction of closing theaperture.
 2. The apparatus of claim 1, wherein the damper body ismounted and movably disposed to rotate so as to selectively open andclose the aperture.
 3. The apparatus of claim 2, wherein the damper bodyis connected to the body frame and is transversely transposable toselectively open and close the aperture.
 4. The apparatus of claim 3,wherein the damper body is connected to the body frame by a mountingmechanism removed from the aperture through the cooperation of a rotaryaxis which is disposed adjacent a second end of the damper body, themounting mechanism having a hinge portion which has an axis mount forreceiving the rotary axis in an upright position and the mountingmechanism protrudes outwardly from the body frame.
 5. The apparatus ofclaim 3, wherein the resilient member further comprises a plate spring,having two ends, which engages the damper body adjacent the first end,and engages the body frame adjacent the second end.
 6. The apparatus ofclaim 1, wherein the resilient member further comprises a plate spring,having two ends, which engages the damper body adjacent the first end,and engages the body frame adjacent the other end.
 7. The apparatus ofclaim 5, wherein one end of the resilient member overlaps the damperbody and the other end overlaps the body frame.
 8. The apparatus ofclaim 6, wherein one end of the resilient member overlaps the damperbody and the other end overlaps the body frame.
 9. The apparatus ofclaim 7, wherein the mounting mechanism further comprises a hingeportion protruding from the body frame, and having a plate engagementsection connected to the second end of the resilient member so as toenable adjustment of the recovery force provided by the resilient memberby adjusting the position with respect to the body frame.
 10. Theapparatus of claim 8, wherein the mounting mechanism further comprises ahinge portion protruding from the body frame, and having a plateengagement section connected with the second end of the resilient memberso as to enable adjustment of the recovery force provided by theresilient member by adjusting the position of the hinge portion withrespect to the body frame.
 11. The apparatus of claim 9, wherein thehinge portion is adjustable in the height to which it protrudes from thesurface of the body frame of the vacuum cleaner.
 12. The apparatus ofclaim 10, wherein the hinge portion is adjustable in the height to whichit protrudes from the surface of the body frame of the vacuum cleaner.13. The apparatus of claim 1, wherein a cap portion is disposed adjacentthe second end of the damper body, and the resilient member furthercomprises a coil spring interposed between the opening/closing portionof the damper body and the cap portion.
 14. The apparatus of claim 13,wherein the coil spring is shaped and configured having a diameter thatis larger than the smallest diameter of the tapered opening/closingportion of the damper body, and is larger than the smallest diameter ofthe aperture.
 15. The apparatus of claim 14, wherein the damper bodycomprises a plurality of holes to permit air to flow therethrough. 16.The apparatus of claim 15, wherein the plurality of holes extend in alengthwise direction of the damper body, thereby defining posts.
 17. Theapparatus of claim 16, wherein the cap portion comprises a plurality ofholes to permit air to pass therethrough.
 18. The apparatus of claim 17,wherein the coil spring is fixed to the body frame adjacent one end, andfixed to the cap portion adjacent the other end.